Battery circuit for supplying power to an electronic device

Abstract

A battery circuit for use in supplying power to an electronic device comprises a first battery source, a second battery source connected in parallel to the first battery source, a first auxiliary circuit for preventing the first battery source from being charged by the second battery source and for preventing a reverse voltage from being applied by the first battery source to the electronic device and a second auxiliary circuit for preventing the second battery source from being charged by the first battery source and for preventing a reverse voltage from being applied by the second battery source to the electronic device. The first auxiliary circuit includes a first MOSFET which has a first switching state and a second switching state and a first operational amplifier for controlling the switching state of the first MOSFET. The second auxiliary circuit is connected in series to the second battery source and includes a second MOSFET which has a first switching state and a second switching state and a second operational amplifier for controlling the switching state of the second MOSFET.

What is claimed is: 
     
       1. A battery circuit for use in supplying power to an electronic device, said battery circuit comprising: (a). a first battery source having a positive terminal and a negative terminal,   (b). a second battery source connected in parallel to said first battery source, said second battery source having a positive terminal and a negative terminal, and   (c). a first auxiliary circuit connected to said first battery source, said first auxiliary circuit comprising, (i). a first switching device having a first switching state and a second switching state, said first switching state allowing current to flow to said first battery source from said second battery source and said second switching state preventing current from flowing to said first battery source from said second battery source, and   (ii). a first switch controlling device for controlling the switching state of said first switching device, said first switch controlling device placing said first switching device in its second switching state when the voltage of said first battery source is less than the voltage of said second battery source so as to prevent all cross-charging of said first battery source by said second battery source.     
     
     
       2. The battery circuit as claimed in claim 1 wherein said first switching device is a transistor. 
     
     
       3. The battery circuit as claimed in claim 1 further comprising a second auxiliary circuit connected to said second battery source, said second auxiliary circuit comprising, (i). a second switching device having a first switching state and a second switching state, said first switching state allowing current to flow to said second battery source from said first battery source and said second switching state preventing current from flowing to said second battery source from said first battery source, and   (ii). a second switch controlling device for controlling the switching state of said second switching device, said second switch controlling device placing said second switching device in its second switching state when the voltage of said second battery source is less than the voltage of said first battery source so as to prevent all cross-charging of said second battery source by said first battery source.   
     
     
       4. The battery circuit as claimed in claim 3 wherein said second switching device is a transistor. 
     
     
       5. The battery circuit as claimed in claim 4 wherein said second switch controlling device is an operational amplifier. 
     
     
       6. The battery circuit as claimed in claim 5 wherein said second transistor is a metal-oxide-semiconductor field-effect transistor (MOSFET) having an N-type channel and including a drain, a gate and a source. 
     
     
       7. The battery circuit as claimed in claim 1 wherein each battery source comprises two batteries. 
     
     
       8. The battery circuit as claimed in claim 7 wherein each battery is 1.5 volts. 
     
     
       9. A circuit connected to a first battery source for controlling the flow of current to the first battery source from a second battery source, the second battery source being connected in parallel with the first battery source, said circuit comprising: (i). a switching device having a first switching state and a second switching state, said first switching state allowing current to flow to said first battery source from said second battery source and said second switching state preventing current from flowing to said first battery source from said second battery source, and   (ii). a switch controlling device for controlling the switching state of said switching device, said switch controlling device placing said switching device in its second switching state when the voltage of said first battery source is less than the voltage of said second battery source so as to prevent all cross-charging of said first battery source by said second battery source.   
     
     
       10. The circuit of claim 9 wherein said switching device is a transistor. 
     
     
       11. A battery circuit for use in supplying power to an electronic device, said battery circuit comprising: (a). a first battery source having a positive terminal and a negative terminal,   (b). a second battery source connected in parallel to said first battery source, said second battery source having a positive terminal and a negative terminal,   (c). a first auxiliary circuit connected to said first battery source, said first auxiliary circuit comprising, (i). a first transistor having a first switching state and a second switching state, said first switching state allowing current to flow to said first battery source from said second battery source and said second switching state preventing current from flowing to said first battery source from said second battery source, said first transistor being a metal-oxide-semiconductor field-effect transistor (MOSFET) having an N-type channel and including a drain, a gate and a source, and   (ii). a first operational amplifier for controlling the switching state of said first transistor, said first operational amplifier having an inverting input, a noninverting input, an output, a collector terminal and an emitter terminal,   (iii). wherein the positive terminal of said first battery source is coupled to the collector terminal of said first operational amplifier and to the electronic device, the negative terminal of said first battery source is coupled to the inverting input of said first operational amplifier and to the drain of said first transistor, the emitter terminal of said first operational amplifier is coupled to the noninverting input of said first operational amplifier and to the source of said first transistor, the noninverting input of said first operational amplifier is coupled to the output of said first operational amplifier and to the source of said first transistor, the output of said first operational amplifier is coupled to the gate of said first transistor, and the source of said first transistor is coupled to a ground, and     (d). a second auxiliary circuit connected to said second battery source, said second auxiliary circuit comprising, (i). a second transistor having a first switching state and a second switching state, said first switching state allowing current to flow to said second battery source from said first battery source and said second switching state preventing current from flowing to said second battery source from said first battery source, said first transistor being a metal-oxide-semiconductor field-effect transistor (MOSFET) having an N-type channel and including a drain, a gate and a source, and   (ii). a first operational amplifier for controlling the switching state of said second transistor.     
     
     
       12. The battery circuit as claimed in claim 11 wherein said second operational amplifier includes an inverting input, a noninverting input, an output, a collector terminal and an emitter terminal, the positive terminal of said second battery source being coupled to the collector terminal of said second operational amplifier and to the electronic device, the negative terminal of said second battery source being coupled to the inverting input of said second operational amplifier and to the drain of said second transistor, the emitter terminal of said second operational amplifier being coupled to the noninverting input of said second operational amplifier and to the source of said second transistor, the noninverting input of said second operational amplifier being coupled to the output of said second operational amplifier and to the source of said second transistor, the output of said second operational amplifier being coupled to the gate of said second transistor, and the source of said second transistor being coupled to a ground. 
     
     
       13. The battery circuit as claimed in claim 12 wherein said first auxiliary circuit further includes first and second resistors for biasing the battery circuit, said first resistor being coupled to the noninverting input of said first operational amplifier and to the output of said first operational amplifier, and said second resistor being coupled to the noninverting input of said first operational amplifier and to the source of said first transistor. 
     
     
       14. The battery circuit as claimed in claim 13 wherein said second auxiliary circuit further includes third and fourth resistors for biasing the battery circuit, said third resistor being coupled to the noninverting input of said second operational amplifier and to the output of said second operational amplifier, and said fourth resistor being coupled to the noninverting input of said second operational amplifier and to the source of said second transistor. 
     
     
       15. The battery circuit as claimed in claim 14 wherein said second auxiliary circuit further includes a capacitor for decoupling noise produced by said battery circuit, said capacitor being coupled to the collector terminal of said second operational amplifier and to the emitter terminal of said second operational amplifier. 
     
     
       16. The battery circuit as claimed in claim 15 further resistor for assisting and a fifth resistor for assisting to control the switching state of said first transistor, said fifth resistor being coupled to said power supply and to the gate of said first transistor. 
     
     
       17. The battery circuit as claimed in claim 16 further comprising a sixth resistor for assisting to control the switching state of said second transistor, said sixth resistor being coupled to said power supply and to the gate of said second transistor. 
     
     
       18. A battery circuit for use in supplying power to an electronic device, said battery circuit comprising: (a). a first battery source having a positive terminal and a negative terminal,   (b). a second battery source connected in parallel to said first battery source, said second battery source having a positive terminal and a negative terminal, and   (c). a first auxiliary circuit connected to said first battery source, said first auxiliary circuit comprising, (i). a transistor having a first switching state and a second switching state, said first switching state allowing current to flow to said first battery source from said second battery source and said second switching state preventing current from flowing to said first battery source from said second battery source, and   (ii). an operational amplifier for controlling the switching state of said transistor.     
     
     
       19. The battery circuit as claimed in claim 18 wherein said first transistor is a metal-oxide-semiconductor field-effect transistor (MOSFET) having an N-type channel and including a drain, a gate and a source. 
     
     
       20. The battery circuit as claimed in claim 19 wherein said first operational amplifier includes an inverting input, a noninverting input, an output, a collector terminal and an emitter terminal, the positive terminal of said first battery source being coupled to the collector terminal of said first operational amplifier and to the electronic device, the negative terminal of said first battery source being coupled to the inverting input of said first operational amplifier and to the drain of said first transistor, the emitter terminal of said first operational amplifier being coupled to the noninverting input of said first operational amplifier and to the source of said first transistor, the noninverting input of said first operational amplifier being coupled to the output of said first operational amplifier and to the source of said first transistor, the output of said first operational amplifier being coupled to the gate of said first transistor, and the source of said first transistor being coupled to a ground. 
     
     
       21. A battery circuit for use in supplying power to an electronic device, said battery circuit comprising: (a). a first battery source having a positive terminal and a negative terminal,   (b). a second battery source connected in parallel to said first battery source, said second battery source having a positive terminal and a negative terminal,   (c). a first auxiliary circuit connected to said first battery source, said first auxiliary circuit comprising, (i). a first transistor having a first switching state and a second switching state, said first switching state allowing current to flow to said first battery source from said second battery source and said second switching state preventing current from flowing to said first battery source from said second battery source, said first transistor being a metal-oxide-semiconductor field-effect transistor (MOSFET) having an N-type channel and including a drain, a gate and a source, and   (ii). a first operational amplifier for controlling the switching state of said first transistor, and     (d). a second auxiliary circuit connected to said second battery source, said second auxiliary circuit comprising, (i). a second transistor having a first switching state and a second switching state, said first switching state allowing current to flow to said second battery source from said first battery source and said second switching state preventing current from flowing to said second battery source from said first battery source, said first transistor being a metal-oxide-semiconductor field-effect transistor (MOSFET) having an N-type channel and including a drain, a gate and a source, and   (ii). a second operational amplifier for controlling the switching state of said second transistor, said second operational amplifier having an inverting input, a noninverting input, an output, a collector terminal and an emitter terminal,   (iii). wherein the positive terminal of said second battery source is coupled to the collector terminal of said second operational amplifier and to the electronic device, the negative terminal of said second battery source is coupled to the inverting input of said second operational amplifier and to the drain of said second transistor, the emitter terminal of said second operational amplifier is coupled to the noninverting input of said second operational amplifier and to the source of said second transistor, the noninverting input of said second operational amplifier is coupled to the output of said second operational amplifier and to the source of said second transistor, the output of said second operational amplifier is coupled to the gate of said second transistor, and the source of said second transistor is coupled to a ground.     
     
     
       22. The battery circuit as claimed in claim 20 wherein said first auxiliary circuit further includes first and second resistors for biasing the battery circuit, said first resistor being coupled to the noninverting input of said first operational amplifier and to the output of said first operational amplifier, and said second resistor being coupled to the noninverting input of said first operational amplifier and to the source of said first transistor. 
     
     
       23. The battery circuit as claimed in claim 21 wherein said second auxiliary circuit further includes third and fourth resistors for biasing the battery circuit, said third resistor being coupled to the noninverting input of said second operational amplifier and to the output of said second operational amplifier, and said fourth resistor being coupled to the noninverting input of said second operational amplifier and to the source of said second transistor. 
     
     
       24. The battery circuit as claimed in claim 23 wherein said second auxiliary circuit further includes a capacitor for decoupling noise produced by said battery circuit, said capacitor being coupled to the collector terminal of said second operational amplifier and to the emitter terminal of said second operational amplifier. 
     
     
       25. The battery circuit as claimed in claim 22 further comprising a power supply and a fifth resistor for assisting to control the switching state of said first transistor, said fifth resistor being coupled to said power supply and to the gate of said first transistor. 
     
     
       26. The battery circuit as claimed in claim 24 further comprising a sixth resistor for assisting to control the switching state of said second transistor, said sixth resistor being coupled to said power supply and to the gate of said second transistor. 
     
     
       27. An auxiliary circuit comprising: (i). a transistor having a first switching state and a second switching state, said first switching state allowing current to flow to said first battery source from said second battery source and said second switching state preventing current from flowing to said first battery source from said second battery source, and   (ii). a operational amplifier for controlling the switching state of said transistor.   
     
     
       28. The auxiliary circuit of claim 27 wherein said transistor is a metal-oxide-semiconductor field-effect transistor (MOSFET) having an N-type channel.